Highly complex and precise structures can now be printed in 3D with a new process.
KIT
The various 3D printing techniques available up until now have been used on polymers or metals, but never on glass. In order to process glass into structures, it has to date been melted and applied using a nozzle, for example. However, the surface turns out to be very rough as a result and the material is porous and has cavities. An interdisciplinary team at Karlsruhe Institute of Technology (KIT) led by the mechanical engineer Dr. Bastian E. Rapp has therefore developed a process that enables glass to be used for additive manufacturing technology.
The researchers mix nanoparticles of high-purity quartz glass and a small quantity of liquid polymer and allow this mixture to be cured by light at specific points. The material that remains liquid is washed out in a solvent bath, leaving only the desired cured structure. The polymer still mixed in this glass structure is then removed by heating. "The shape initially resembles that of a pound cake. It is still unstable, and therefore the glass is sintered in a final step, i.e. heated so that the glass particles are fused", explains Rapp. The researchers have presented the process in the journal "Nature" under the title "Three-dimensional printing of transparent fused silica glass".
The glass structures made by the KIT scientists have resolutions in the range of a few micrometres. However, the structures may also range up to a few centimetres according to Rapp. 3D-formed glass could be used, for instance, in optics, data transmission and biotechnology.